Laser energy has been used by many for transurethral incision of small, obstructive prostates, vesical neck contractures, and urethral strictures. The customary techniques of moving the tip of the laser fiber through a cystoscope with a conventional laser guide, almost tangentially to the tissue to be incised, or drilling radially arranged holes in the scar, or both, have been cumbersome and imprecise. To provide exact control of the laser fiber and precise delivery of laser energy, a new guide was devised. It conducts the quartz fiber through the sheath and along the lens of an optical urethrotome. The tip of the quartz fiber contacts the tissue at an angle of 20 degree(s). KTP/532 laser energy is used to perform internal urethrotomy for urethral stricture, transurethral incision of postoperative contracture of the vesical neck, and transurethral incision of the small prostate under constant visual control. Recently, a straight version of this guide, called probe director, was devised to conduct the newly marketed lateral firing laser probes. This probe director allows precise control of such a probe within the prostatic urethral lumen and excellent maneuverability of the probe during transurethral laser prostatectomy.